De or het herstelbemiddeling?

The correct Dutch article is:

de herstelbemiddeling

Rule Words ending in -ing: almost always de. See the rule

How to use herstelbemiddeling

the herstelbemiddelingde herstelbemiddeling
this herstelbemiddelingdeze herstelbemiddeling
that herstelbemiddelingdie herstelbemiddeling
our herstelbemiddelingonze herstelbemiddeling
your herstelbemiddelingjouw herstelbemiddeling
every herstelbemiddelingelke herstelbemiddeling
which herstelbemiddeling?welke herstelbemiddeling?
a big herstelbemiddeling / the big herstelbemiddelingeen grote herstelbemiddeling, de grote herstelbemiddeling